Researchers at the Vienna University of Technology may call this nano 3D printer a "two-photon litography," but I think the better term is "sorcery." Here's how the high-precision-3D-printer, which can create objects with nano-scale precision work:
The 3D printer uses a liquid resin, which is hardened at precisely the correct spots by a focused laser beam. The focal point of the laser beam is guided through the resin by movable mirrors and leaves behind a polymerized line of solid polymer, just a few hundred nanometers wide. This high resolution enables the creation of intricately structured sculptures as tiny as a grain of sand. “Until now, this technique used to be quite slow”, says Professor Jürgen Stampfl from the Institute of Materials Science and Technology at the TU Vienna. “The printing speed used to be measured in millimeters per second – our device can do five meters in one second.” In two-photon lithography, this is a world record.
The race car above is 285 µm wide, about the width of 3 strands of human hair: Link